
class Animal:
    def speek(self):
        pass

class Dog(Animal):
    def speek(self):
        print("汪汪")

class Cat(Animal):
    def speek(self):
        print("喵喵")

def make_noise(animal:Animal):
    animal.speek()

dog_1 = Dog()
cat_1 = Cat()

make_noise(dog_1)
make_noise(cat_1)